The longest ever flight was 64 days in a Cessna 172 (2021)
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It’s 82 feet long but only 166 pounds, and solar refuels it’s batteries. Hardly the same class, but interesting nonetheless.
https://www.overtdefense.com/2022/08/20/airbus-zephyr-crashe...
I realize we'll never hear about it, but I'd be very interested to see what caused it.
https://www.atsb.gov.au/publications/investigation_reports/2...
"While climbing through 8,000 ft above mean sea level, the UAV experienced a series of uncommanded turns. The UAV self-recovered from the first two uncommanded turns however, the third upset resulted in the aircraft entering an uncontrolled spiral descent. Despite attempts to return to controlled flight, the UAV sustained an in-flight break-up."
I can only imagine the control systems that go into these gliders.
Fun fact, most planes are inherently stable, just like paper planes. If there is a disturbance, they will self correct most of the time. For example, glider pilots, if they do something stupid, are instructed to just let go of the controls, and the glider recovers on its own very quickly. Few ways this can go wrong: the wings start to "flap" by vibrating to a resonant frequency, in which case they need to change something, and also spiraling down towards the earth: not because the plane would not recover eventually, but because it might experience high forces that destroy them before recovery can happen.
Few planes are inherently un-stable: meaning they cannot keep flying without constant input, only examples I know of are fly-by-wire modern fighter jets (4th generation onward) and planes with weird shapes like the B2 bomber.
I don't think there is too much control put into these gliders for second to second operations, they are probably just letting it fly forward, with the control being: point it in a very general direction and don't lose contact with it.
And if the tail controls aren't suitably sized, then the pilots won't have enough control authority to move of of the very stable ballistic arc the plane wants to travel on.
That is why recovery from a spiral dive is something that a glider pilot usually has to do as part of a demonstration of proficiency. I get to do one every year as part of my seasonal check flights.
These high altitude, long duration UAVs have really long wings. So the control system would have to work to overcome the tendency to overbank. At some point the tendency to overbank might overcome the authority of the controls.
> Refuelling was handled by lowering a hook via a winch down to a fuel truck that would trail the plane on a straight stretch of road, usually twice a day. The winch would then pull up a fuel hose from the truck, which would be used to fill the belly tank in around three minutes. The same system was used to regularly pull up food, oil and other supplies like towels and water for shaving and bathing.
Midair refueling is the realm of air forces and these guys did it with a hook on a winch.
(also jet engines are really inefficient at low altitudes and it takes a lot of fuel to climb, so the other point is so that fighters don't expend the fuel getting back to altitude again)
The trickiest thing to me about what the Keys did was oil changes, which they needed to do every three days. They rigged up a metal catwalk around their engine, so that Fred could walk out and change the oil from the outside while the plane was still flying (they had two oil systems, each of which could lubricate the entire plane, so every three days they turned off the oil system on one side, Fred climbed out, drained the oil out on the ground- it's the 1930's, no one needs environmental impact statements!) closed the valve and refilled the oil tank, then they turned on that side and turned off the other side and did it again a few hours later when that oil had cooled.
Both Fred and Al joined the USAAF during World War Two and flew bomber missions over Germany. Al stayed in the Air Force after the war and ended up as a Colonel.
That’s surprising! Do you mean the entire life of the engine, or just one run? If the former, doesn’t that get expensive? I imagine that’s not very sustainable.
More importantly: if your car engine dies you gradually slow down and pull over. If your plane engine dies calmly pulling over isn't an option. It's much easier to justify spending the money ensuring a plane's engine is reliable.
I'd say that's closer to going 110km/h or 65mph in 2nd or 3rd gear for most cars.
Highway cruising might take 20-40 HP depending on your vehicle, which is probably more like 10% of rated power. 70% of rated power in a typical American car is probably like 120 MPH.
18K gallons will take a typical road car around 500K miles, so an airplane engine getting "only 1800 hours" of flight time likely outperforms the typical auto engine.
It'll take a normal private pilot a few years to reach 1800h of operation, so it's more economical if you're not flying the plane continuously for weeks at a time.
But yeah, it's expensive. Owning a plane is expensive. It depends on if it's worth it to you to operate the plane. Small single-engine planes like the Cessna 172 are commonly used for recreation or training. So if you use it often, such frequent overhauls will pay for themselves in terms of safety and reliability.
Maybe when all-electric recreational aircraft become common they won't have to be maintained quite so much...
Turboprop engines (effectively these are jet engines with propellers attached) like the ubiquitous P&W PT6A have TBOs up to 4,500 or even 6,000 hours.
(I work on another electric airplane which will take flight in 2023.)
https://www.aopa.org/news-and-media/all-news/2008/march/pilo...
> The danger of in-flight bathing
> In his diary, John Cook wrote, “We got a quart of bath water, a large towel and soap every other day.”
> On January 12, 1959, after refueling chores, Timm removed his clothes and stepped out onto the platform for a refreshing sponge bath. He started by brushing his teeth. Just then Cook realized that the airplane wasn’t going to clear an upcoming ridge if the platform wasn’t pulled in. Cook yelled at Timm to pull in the platform and later told of seeing his partner struggling to complete that task—buck naked, and weighing 240 pounds, with a toothbrush sticking out of one side of his mouth and toothpaste streaming out of the other. They cleared the ridge but learned to delay hygienic activities until they were over flatter terrain.
> After the first three flights, the plane had never stayed aloft longer than 17 days.
Imagine going up there a third time, spending a day, then two, then a week, then two weeks, and then a few days later being forced to land... only to get up there again aiming for two months!
> Before he passed away in 1978, Timm reminisced about his flying days and told his sons that he longed to locate 72B. His father’s wish eventually prompted Timm’s second son, Steve, to launch a focused effort to find and return N9172B to Las Vegas. He found it on a farm in Carrot River, Saskatchewan, Canada. He brought it back to Las Vegas in 1988. In 1992 the McCarran Aviation Heritage Museum (now the Howard W. Cannon Aviation Museum) obtained 72B for a permanent exhibit. It’s been restored to its pre-flight condition.
> Today, N9172B is back in Las Vegas. The 1958 Cessna 172 that holds the world endurance flight record hangs from the ceiling of the baggage claim area at McCarran International Airport. Next time you fly in to Las Vegas, take a minute to look up at one of the most prosaic record-setting airplanes in the world. And imagine what it must have been like to spend more than two months living in a Cessna 172.
https://www.audubon.org/news/the-common-swift-new-record-hol...
So we're looking at only a cool $135 million.
So I'd say this record is very unlikely to be beaten!
[1] https://www.damninteresting.com/the-unceasing-cessna-haciend...
https://www.aopa.org/news-and-media/all-news/2008/march/pilo...
https://flightaware.com/live/flight/N490NW/history/20220820/...
Are there any more details available about this, or is there just that FlightAware log? How does one ensure they have enough fuel to do this?!
It is an interesting thing though, the same planes that go fairly cheap in Canada are worth a fortune here in Europe so there definitely is money to be made.
Both airplanes came in a number of variants. The Aerobat variant of each was rated to +6/-3g due to structural improvements. It had other aerobatic features like a quick release door, four point harness and skylights. You might be able to identify them by their checkerboard paint job. Less than 4% of 150/152s were Aerobats.
"Aerobat" is a brand name specific to Cessna. You can do some amount of aerobatics in any trainer, like steep turns or a lazy eight. The FAA defines "acrobatic", which specifically excludes those maneuvers and a few more. There's an associated Aerobatic Category of aircraft.
Good little airplanes, they are.
I suppose they chose their engine airspeed to achieve the lowest fuel consumption rate https://www.se.edu/aviation/wp-content/uploads/sites/4/2020/... See pdf page 132, book page 5-18. It looks like they could use as little as ~6 gallons/hour at 1900 rpm. You can save a lot of fuel by flying more slowly; handy to know if you need (heaven forbid) to stretch that 45-minute reserve when your destination is socked in.
https://www.futilitycloset.com/2018/03/05/podcast-episode-19...
Honorable mention goes to the Swedes with the Saab Viggen who managed to get missile lock on the SR-71 as it cruised through a narrow corridor past their airspace. The Viggen wasn't fast enough on its own, but much like modern cannonball runs, careful planning and coordination made it possible.